QRix
Make the compact square-with-a-bullseye code that rail and airline tickets use — it fits where other 2D codes will not.
Compact 2D code common on transport and event tickets — scans without a quiet zone.
Uses the format, color and size selected above — one PNG per line, zipped.
Aztec Code is named for the stepped bullseye at its centre, which resembles an Aztec pyramid viewed from directly above. That central finder pattern is the format's defining trick: because the scanner locks onto the middle rather than hunting for corner markers, an Aztec symbol needs no quiet zone at all. Every other 2D code demands a blank margin around it, so on a crowded ticket stub or a narrow luggage tag Aztec reliably wins the space argument — often by twenty to thirty percent. It is standardised as ISO/IEC 24778, holds up to roughly 3,000 characters, and lets you dial error correction anywhere from five to ninety-five percent, with twenty-three percent as the sensible default. Deutsche Bahn, SNCF, Trenitalia and most European rail operators print Aztec on mobile and paper tickets for exactly these reasons.
Rail and bus tickets
Airline boarding passes
Event and cinema admission
Narrow labels where a quiet zone will not fit
Vehicle and insurance documents
Mostly in transport and ticketing: European rail tickets, airline boarding passes, event admission, some vehicle registration documents, and Czech and Slovak payment slips.
Its finder pattern is a bullseye in the centre of the symbol rather than markers at the corners, so a scanner can locate and lock onto the code without a blank margin telling it where the edges are.
Up to about 3,000 alphanumeric characters or 3,800 digits, depending on the error-correction level you accept.
Use QR when a phone camera is the reader and you have room. Use Aztec when space is tight, when you need no quiet zone, or when you are matching an existing transport-industry system that already expects it.
Most dedicated barcode apps and every ticket-validation scanner read Aztec. Some built-in phone camera apps only look for QR, so test with a general barcode reader if the code is meant for consumers.
It's free, private and works right in your browser — no signup, no watermark.